Presentation (CTI)

OBJECTIVES: Vasomotor symptoms (VMS) caused by adjuvant endocrine therapy (AET) in women with breast cancer (BC) are frequent, persistent, and reduce quality of life, with limited treatment options available. This analysis estimated EQ-5D-3L health state utility values associated with VMS, overall and in women initiating AET within the prior 6 months (reflecting patients who recently began experiencing symptoms), to quantify the utility burden and subsequent improvement linked to ≥50% reduction in the frequency of moderate-to-severe VMS.
METHODS: This is a post-hoc analysis using data from the OASIS-4 trial (NCT05587296) of elinzanetant versus placebo. EQ-5D-3L index (UK tariff, mapped from EQ-5D-5L using Hernández Alava et al. (2023)) [a standardized measure of health-related QoL anchored at 0 (death) and 1 (perfect health)] was modelled using mixed model for repeated measures with a time-dependent covariate for VMS response (≥50% reduction in moderate-to-severe hot flash frequency; yes/no). Women initiating AET within the prior 6 months were included as a subgroup.
RESULTS: 474 patients were included in the analysis, with 74 women initiating AET within the prior 6 months; at baseline, mean utility was 0.728 overall and 0.712 within the subgroup. In the overall population, EQ-5D-3L was significantly associated with VMS response (yes: 0.780 vs. no: 0.752; difference 0.028, p<0.001). Among those initiating AET within the prior 6 months, larger differences were observed by VMS response (yes: 0.780 vs. no: 0.738, difference 0.042).
CONCLUSIONS: VMS have measurable impact in women receiving AET for breast cancer, and VMS relief is associated with a meaningful utility gain. Women who recently initiated AET and began experiencing VMS had lower baseline utility and showed a pronounced utility improvement with elinzanetant treatment.